The terms ‘eczema’ and ‘dermatitis’ are synonymous; they are general terms for conditions that cause inflammation (redness, swelling, heat, and pain) of the skin. Eczema can be acute (severe and sudden in onset) or chronic (developing over a long period), and there are several causes.
Classification of eczema
- Endogenous: Having an internal cause or origin (e.g. atopic, seborrhoeic).
- Exogenous: Having an external cause or origin (e.g. irritant, allergic, photoallergic, actinic dermatitis).
Atopic eczema/dermatitis
Atopy is a state in which there is a genetic predisposition for one’s immune system to produce excess antibodies, leading to hypersensitivity to common environmental substances (antigens) such as pollen and house dust mites. Atopic individuals may exhibit one or more conditions, including asthma, hay fever, food allergies, and atopic eczema.
Diagnosis
Genetic factors contribute to decreased skin barrier function, allowing greater penetration of allergens through the outermost layer of the skin (epidermis), triggering immune stimulation and subsequent inflammation. Environmental factors, such as exposure to allergens in the womb or during childhood, also play a role.
Epidemiological studies indicate that 60–80 percent of individuals are genetically susceptible to antibody-mediated sensitisation to environmental substances that can trigger immune reactions, such as food and animal hair.
Clinical features
Atopic eczema is extremely itchy, and scratching accounts for many of its symptoms. Widespread skin dryness (roughness) is another characteristic feature. The distribution varies with age:
Babies and infants
- Often acute with prominent facial involvement.
- The trunk may be affected, but the nappy area is usually spared.
Children
- Affects areas behind the knees, elbows, wrists, and ankles.
Adults
- Commonly affects the face and trunk, with limb involvement.
Complications
There is a risk of developing widespread infections, particularly from the herpes simplex virus (HSV) and fungal infections.
General management of eczema
The primary aim of treatment is to limit water loss from the skin. This is achieved through regular use of emollients (such as emulsifying ointments), which are essential for all types of eczema. Emollients can be used as bath additives, soap substitutes, and direct skin applications, often combined with antiseptics.
The skin should be tested for infections, and any detected infections should be treated accordingly.
Remission
The possibility of long-term remission varies among individuals and depends on the treatment strategy they follow.
